Disordered Eating Behaviours

The primary outcome variable disordered eating behaviours will be measured through the Three Factor Eating Questionnaire-Revised 21 (TFEQ) in adults. The primary outcome for youth (12 to 17y) is the Child Three Factor Eating Questionnaire 17, which is an adapted questionnaire from the TFEQ. TFEQ refers to current dietary practice and measures 3 different aspects of eating behaviour: cognitive dietary restraint (conscious restriction of food intake) score ranges from 6 to 24, uncontrolled eating (tendency to eat more than usual due to loss of control over intake accompanied by subjective feelings of hunger) score ranges from 9 to 36, and emotional eating (inability to resist emotional cues) score ranges from 6 to 24. Higher scores in the respective scales indicate greater level of restrained, uncontrolled, or emotional eating.

Collected at one time point per participant at the time of survey completion. The study has an observational, cross-sectional design from April 2024 to estimated May 2026.

Diabetes Disordered Eating Behaviours

The Diabetes Eating Problem Survey (DEPS-R) is a 16-item questionnaire for youth and adults over the age of 12 years. It refers to disordered eating behaviours specific to people with type 1 diabetes. The score ranges from 0 to 80, with a higher score indicating higher risk of disordered eating.

Collected at one time point per participant at the time of survey completion. The study has an observational, cross-sectional design from April 2024 to estimated May 2026

Orthorexia Eating Behaviours

The Teruel Orthorexia Scale is a 17-item questionnaire, that is validated in both English and French. It measures 'healthy orthorexia' behaviours as well as behaviours related to 'orthorexia nervosa'. Healthy orthorexia describes individuals who have a high interest in healthy eating, but in a non-pathological dimension of orthorexia. This sub scales score ranges from 0 to 27. Orthorexia nervosa includes behaviours that are related to healthy eating that may cause malnutrition, emotional distress, and social impairment. This subscale ranges from 0 to 24. A higher score represents more orthorexia symptoms.

Collected at one time point per participant at the time of survey completion. The study has an observational, cross-sectional design from April 2024 to estimated May 2026

Glucose Time In Range (TIR)

Time in Range (TIR) (%): glucose TIR is the percentage of time that glucose levels are between 3.9 and 10.0 mmol/L. A higher TIR indicates improved glycemic levels. Guidelines recommend a TIR greater than 70% for most PwT1D.

Collected at one time point per participant at the time of survey completion. The study has an observational, cross-sectional design from April 2024 to estimated May 2026.

Coefficient of Variation (CV)

Coefficient of Variation (CV) is determined by dividing the standard deviation of blood glucose levels over a 14-day period, by the total mean glucose and multiplying by 100 to obtain a percentage. This value reflects the variability of glucose levels. A higher CV value indicates more glycemic variability.

Collected at one time point per participant at the time of survey completion. The study has an observational, cross-sectional design from April 2024 to estimated May 2026.